/**
 * Copyright 2000 self.com.au
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License. (http://www.apache.org/licenses/LICENSE-2.0)
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for 
 * the specific language governing permissions and limitations under the License.
 *
 * <dhamma-message src="Atisha (11th century Tibetan Buddhist master)">
 * 	The greatest achievement is selflessness. The greatest worth is self-mastery.
 * 	The greatest quality is seeking to serve others. The greatest precept is continual awareness.
 * 	The greatest medicine is the emptiness of everything. The greatest action is not conforming with the worlds ways.
 * 	The greatest magic is transmuting the passions. The greatest generosity is non-attachment.
 * 	The greatest goodness is a peaceful mind. The greatest patience is humility.
 * 	The greatest effort is not concerned with results. The greatest meditation is a mind that lets go.
 * 	The greatest wisdom is seeing through appearances. 
 * </dhamma-message>
 *
 * @author Ashin Wimalajeewa
 */
package self.amigo.tool;

import javax.swing.*;

import self.gee.editor.*;

import self.amigo.module.*;

public class UndoManager {
  private IDiagramEditor           editor;
  private JMenuItem               editUndoItem;
  private JMenuItem               editRedoItem;
  
  public UndoManager( IDiagramEditor ed ) {
    editor = ed;
  } 
  
  public void initMenus( IEditingHost host ) {
    editUndoItem  = (JMenuItem) host.getValue( IEditingHost.EDIT_UNDO_MI_KEY );
    editRedoItem = (JMenuItem) host.getValue( IEditingHost.EDIT_REDO_MI_KEY );
  }
  
  public void resetMenus( CommandManager history ) {
    boolean canUndo = history.canUndo();
    boolean canRedo = history.canRedo();
    editUndoItem.setEnabled( canUndo );
    editRedoItem.setEnabled( canRedo );
  }
  
  public void activateMenus( boolean activate ) {
    editUndoItem.setEnabled( false );
    editRedoItem.setEnabled( false );
  }
  
  public void     undo() {
    editor.executeCommand( ICommand.ET_UNDO, ICommand.VOID_COMMAND );
  }
  
  public void     redo() {
    editor.executeCommand( ICommand.ET_REDO, ICommand.VOID_COMMAND );
  }
}